Propeller driving mechanism



Jan. 2, 1940. M M. EGAN 2,185,545

' PROPELLER DRIVING MEGHANISM I Filed Jan. 23, 1959 2 Sheets-Sheet 1 Mathew/l E am l VENTOR ATTORNEYS Jan. z, 1940.

M. M, EGAN PROPELLER DRIVING MECHANISM Filed Jan. 25. 1939 2 sheets-shea 2 AINVENTOR' ATTOR NEYS Patented Jan. 2, 1940 PATENT OFFICE PnoPELLER Darvmc. 'MEonANIsM Mathew M. Egan, Fort worth, Tex. Application January 23, 1939, Serial No. 252,456

5 claims.

This invention relates .to propeller driving mechanisms, and its general object is to provide a driving mechanismprimarily designed for twin propellers of aircrafts, that includes a housing 6 constructed especially to facilitate readily changing of the gears of the mechanism, sothat different sets of gears can be used and variedin accordance with'the speed of the engine and the desired speed and direction of rotation of the' l propellers.

A further object is to provide a driving mechalnism for twin propellers that makes provision for thorough lubrication of the parts, asgwell as ample and firm supporting means for the gears 15 and propeller shafts, so las nate friction and vibration to a minimum.

Another object is to provide a driving mechanism for twin propellers by which the latter can be driven from a common power shaft in the 20 same or opposite directions, at the same or different speeds, and at a greater or less speed than the normal speed of the engine, and such is brought about by the gear arrangement andthe easy gear changing feature previously referred to. .25 A still further object isto provide a driving mechanism of the'character set forth, that is simple in construction, ture, easy to install and extremely eiiicie'nt in operation. use and service. f

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specically pointed out in the 'appended claims.

'I Y In describing -the invention in detail, reierencev will be had to the yaccompanying drawings wheref in like characters denote like or corresponding parts throughout the several views, and in which:

n Figure .1 is a Ivertical sectional view'taken through my driving mechanism, with parts in elevation and illustrates fragmentary portions of tlhe twin propellers "applied to their respective ubs.

Figure 2 is a front elevationl of my mechanism with the propellers applied thereto. Figure 3 isla sectional view'taken approximatelyon line 3-3of Figure 1, looking in the direction of the arrows.

50 Figure 4 is a sectionalview taken approximately on line 4-4 of Figure 1, looking in the directions `of the arrows. v

Figure is a fragmentary' sectional view illustrating the mounting of the idle gear of the gear .5 5 train for the front or' slow propeller.

to reduce and ellmi inexpensive to manuiaccentrically arranged (Cl. 'ILL-389) Referring to the drawings in detail, the reference numeral I indicates the engine casing to which is fixed the housing of my mechanism by any suitable means, such as screw bolts, while 2 indicates the engine shaft and 3 the shaft for the front-propeller, in the form of mechanism The housing 'of my mechanism includes a rear section l having its main or vertical wall 5 bearing against the engine casing, and formed on the wall 5 is a flanged marginal wall portion 1 having the ange 8 thereof extending outwardly at right angles `with`respect thereto, for receiving the marginal edge portion of the vertical wall 9 of an intermediate or partition section I0, the latter cooperating with the rear section and a front section II to provide the housing of my mechanism and the 'front section also includes a flanged marginal wall portion I2 having the flange I3 ythereof engaged with the marginal edge portion pf the intermediate section, the flanges and the marginal edge portion each: being provided with registering openings for receiving bolt and nut connections Il for detachably securing the sections in housing formation, as best shown in Figure 1. c

The housing is substantially flat oval shape to .provide an enlarged rounded upper portion and a relatively small lower portion, and -the vertical wall of the front section has a circular opening in the enlarged portion thereof through which I5 providing what might be termed a boxing which is formed on and extends outwardly from the partition section to provide a bearing support for the respective shafts 3 and I6, the shaft- 3 extending through the sleeve I5, asvwell as through v`openings in the vertical wall 5 and the partition section Ill and is conand mounted accordingly in bearings I1, while surrounds the sleeve I5, but is with respect to 'the sleeve'v spaced therefrom by being mounted upon bearyings I8,=which like the bearings I1 are of the roller'type, in the form as shown.

' The Aouter end of the cylindrical'shaft isclosed by a ring cap I9 that is threaded to the shaft and acts to hold lubricant sealing members 2li and 2I in place between the shaft I6 andthe sleeve I5, as well las between the latter and the shaft 3, andA a lubricant sealing member 22 is likewise provided about the edge of the opening of the front section I-I., for `engagement-with the shaft I6, as clearly shown in Figure 1. Keyed to the shaft I6 is a hub 23 for the rear p opeller 2l and'is held thereon by the ring cap I9 while keyed to the reduced end of the shaft 3 is the hub 25 for the front propeller 26 that is held accordingly by a nut as shown.

The engine shaft 2 extends through bearing openings in the lower portions of the rear and intermediate housing sections and has its outer end mounted in a roller bearing 21 secured within a circular boss 28 disposed about an opening in the vertical wall of the front section, the latter opening being closed by a disk plateu29.

It will be noted that I have illustrated one set of gears for -each of the propellershafts and the ratio of the gears of the set for the front propeller shaft is approximately two to one while the ratio for the gears of the rear propeller shaft is approximately three to four, and the latter set includes two gears while the former includes three, but both sets may include only two gears and the gears may be of any size, with the result it will be seen that the speed and direction of rotation of the propellers may be varied merely by changing the gears, and the detachable association of the housing sections together with the removability of the other elements makes it possible to change the gears in an easy and expeditious manner.

The set of gears shown, as being in use in the drawings for driving the front propeller shaft, includes what I term a bull or power pinion 30 keyed or otherwise secured to the engine or drive shaft 2, between the rear and intermediate sections, and an idle gear 3| secured to a stub shaft 32 mounted in roller bearings 33, within openings in the parallel or vertical walls of the latter sections. That structure is clearly shown in Figure 5, and it will be noted that the openings are closed by disk plates. The idle gear meshes with the pinion 30 and with a reducing gear 34 keyed to the shaft 3. The bull or power pinion 35 for the set of gears for the rear propeller isL likewise shown as being keyed to the engine shaft and directly meshes with the gear 36, which may be keyed to the hollow shaft I6, but is shown as being integral therewith, and the gear 36 bears against an anti-friction bearing 31 of the ball type, disposed between the same and the front section H, as clearly shown in Figure 1. By using the idle gear 3| and the other gears of the ratio shown and previously set forth, it Will be obvious that the propellers will be rotated in opposite""directions and the rear propeller will be rotated at a speed of approximately one and onehalf times greater than that of the front propeller, but when gears of different ratio are substituted for those shown, the relative speed of the propellers will be changed, and if the idle gear 3l is removed and the gears of the front propeller are of a size to mesh with each other, the front propeller will rotate inthe same direction as the rear propeller, as will be apparent. I'

, It will be furtherrobvious that the propeller shafts are amply supported by the use of the intermediate or partition section and the fixed sleeve formed thereon, while the projecting portion of the engine shaft is likewise amply supported, and the supporting features coupled with the bearing arrangement will eliminate or reduce vibration of the parts to a minimum at all speeds of the engine and propellers.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination shaft, marginal and arrangement of the several parts, provided that such changes fall within the scope of the appended claims.

What I claim is:

1. A mechanism for driving twin propellers of an aircraft from a common drive shaft, and comprising a sectional gear housing, a shaft for each propeller and concentrically arranged with each other, a section of the housing including a sleeve integral therewith and extending through the housing for disposal exteriorly thereof, said sleeve providing a support for and disposed between the propeller shafts, bearings for the propeller shafts and disposed between the latter and the sleeve, gears for each propeller shaft for individually rotating the same in oppositev directions from the drive shaft, and the being removably secured togetherl whereby to allow access to the gears for substituting therefor gears of a different number and ratio to vary the direction of rotation of the propellers and speed'- sections of the housing thereof in accordance with the speed of the drive providing a support for and disposed between the propeller shafts, gears for each propeller shaft for individually rotating the same from the drive anges formed on the rear and means for securing the iianges to edge portion of the intermediate each other whereby access may gears for substituting therefor gears of a dierent number and ratio to vary thedirection of rotation of the propellers and speed thereof in accordance with the speed of the drive shaft.

3. A mechanism for driving twin propellers of an aircraft from a common drive shaft, and comprising a gear housing including rear and front j an intermediate partition section, a

sections and shaft for one of said propellers, a shaft for the other propeller and surrounding the :first propeller shaft, a sleeve integral with the partition sec' tion and extending at right angles therefrom for disposal through the front section, said sleeve providing a support for and disposed between the propeller shafts, bearings for the propeller shafts and disposed between the latter and the sleeve, a set of gears for each propeller shaft for rotating the same from the drive shaft, the sets of gears being of different ratio for rotating the propeller shafts at different speeds, an idle gear in one of said sets of gears for rotating one drive shaft in a direction opposite to that of the other, and means for detachably securing. the sections together in housing formation.

4. A mechanism for driving twin propellers of an aircraft Afrom a common drive shaft, and comprising a. gear housing including rear and front sections and an intermediate partition section, aiy shaft for one of said propellers and extending through said housing, a hollow cylindrical shaft for the other propeller and surrounding the rst propeller shaft, a sleeve integral with the partition section and extending at right angles therefrom for disposal through the front section, said sleeve providing a support forvand disposed for the other propeller 5. A mechanism between the propeller shafts. bearings for the propeller shafts and disposed between the latter and the sleeve, a cap for the outer end of the hoilow propeller shaft, lubricant sealing means between the sleeve and propeller shafts and between the casing and the hollow propeller shaft. each of said sections provided with bearings for the drive shaft, a set of gears for each propeller shaft for individually rotating the drive shaft, and means the sections together in housing formation.

for driving twin propellers of an aircraft from a common drive shaft, and comprising a gear housing including rear and front sections and an intermediate partition section, a shaft for one of said propellers, a hollow shaft andsurrounding the first propeller shaft, a sleeve integral with .the vpartition'section and extending at right angles therefrom for disposal through the front section, said sleeve providing a lsupport for and disposed be- "ill same from theA for detachably securingleach of the propeller shafts gear for rotating the hollow tween the propeller shafts, Efor the propeller shafts and disposed between the latter and the sleeve. each 'of said sections provided with bearings for the drive shaft, a set of gears for for rotating the same from the drive shaft. the set of gears for the nrst propeller shaft including a relatively small gear keyed to the drive shaft, a relatively large gear keyed to the first propeller shaft. an idle gear meshing with the relatively small and large gears for rotating the first propeller shaft in the same direction as this of the drive shaft, the ses of gears for the hollow shaft including a relatively small gear keyed to the drive shaft and a relative large gear fixed to the hollow propeller shaft and meshing with the second mentioned small propeller shaft in a direction opposite to that of the other propeller shaft, and. means for detachablyv securing the sections together in housing formation.

` MATHEW M. EGAN. 

